1. Field of the Invention
The invention relates to a method for fabricating a semiconductor substrate, a battery and a method for fabricating the same. More particularly, the invention relates to a method for fabricating a p-type semiconductor substrate, a solar cell and a method for fabricating the same.
2. Description of Related Art
Energy supply of fossil fuels has become increasingly scarce, and the burning of fossil fuels brings environmental and air pollutions. Although nuclear power generation is able to supply a high power density, there are security concerns of nuclear radiation and nuclear waste storage. The former two both share a problem of increasing the social costs; and therefore, under considerations and needs of a cut expenditure and developments of clean/less polluting new energy and industrial technology, renewable energy has gradually come to attention, and various countries are all actively researching on the feasibility of using the renewable energy as an alternative energy.
In the renewable energy mentioned above, solar cell may convert sunlight into electricity, and thus solar energy has become one of the mainstreams in alternative energy. Solar cell technologies, as of today, may generally be divided as single crystal silicon solar cells, polycrystal silicon solar cells, amorphous silicon (a-Si) thin film solar cells, III-V solar cells and organic solar cells. In terms of the polycrystal silicon solar cells, fabrication steps thereof are tedious, such that these steps include acid etching, high temperature furnace pipe diffusion, plasma enhanced chemical vapor deposition, electrode screen printing and sintering. The fabrication process mentioned above requires spending a large number of equipments, energies and time costs, and thus a fabrication cost of this type of solar cell is unable to be significantly lowered. In more detail, the conventional polycrystal silicon solar cell includes a p-type semiconductor substrate. A fabrication cost of a polysilicon layer on the p-type semiconductor substrate is accounted for more than half of the fabrication cost of the entire polycrystal silicon solar cell. The main reason is that, nearly 90% of polysilicon materials are wasted during a process of slicing and grind polishing the p-type semiconductor substrate, and thus the cost of the conventional polycrystal silicon solar cell is unable to be significantly lowered.